Logo

PCM 351 wont restart when warm, compression?

PieterJanssen

New member
Hi
my PCM 351 runs beautifully after cold start. after running for like 30 minutes, it won't start again. nothing happens that looks like starting.
can this be compression failure?

I bought a new carb last year, it had a leaking float however, so huge quantities of fuel have entered the engine, which was running poorly, i think it ran like this for 3 times 10 minutes (can this have ruined my engine?)

any ideas?
best regards
Pieter
 
.....after running for like 30 minutes, it won't start again. nothing happens that looks like starting.
Rather vague and useless description......will it crank over? cranks over but won't start? cranks over and starts but wont stay running??

Being as the engine still starts, the former fuel issue may have an adverse impact on the bearings' service life....but doesn't sound like any major issue now. As long as the oil has been changed and the engine run at temperature, you should have mitigated any further degrade.

Describe what happens at the end of the 30 minute interval, right before and after the engine is shut off - and what you do to try and restart it....
 
Dear makomark,
thanks for responding, i changed the oil immedeately after the fuel incident

i meant to say that the engine turns (cranks?) when i turn the ignition key, but it does not start, nor does it make any sound that it is going to start, sorry for the laymens terms. like it has no fuel or no spark

when i pump it a couple of times after a while i can smell some fuel, to no avail.

by the way, the 30 minutes is not exact, when i keep enough throttle it will keep running for an hour etc. Then, when i switch it off and try to start immedialtely, it does nothing, also not after 10 minutes, i have to wait for a really long time

thanks
pieter
 
Last edited:
layman's terms are good by me...just use the best (most accurate) description.

understand the 30 minutes isn't exact....i suspect the issue only occurs once the engine is thoroughly warmed up.....

so what happens before and after the shutdown - wont restart issue? Cruising, skiing,etc??? the details matter so capture as many as you can....

BTW where are you located, geographically?
 
Hi,
I am in the Netherlands. My boat is a 1961 Chris Craft Ski 17'. The original engine was replaced mid 80's. I think.
So the engine runs beautifully from the cold start, cooling water and exhaust look fine. And in the first 10 minutes in the dock, I can switch off and start again, no problems there. When driving there is good power for skiing and towing tubes. Without any load it runs at top speed effortlessly, increasing throttle without problems.

And then, when I switch off, and try to start immediately, it cranks, but no starting, also not after 5 minutes 10 etc.
I could record this in sound or video is it would hel.
Thanks
Pieter
 
when you shut the engine off after a long run, do you let it idle for a few minutes to dump some heat or do you just turn the key to off??

When you go to start it after the engine has sat, do you advance the throttle any or just leave it closed?
 
I let it run for about 1 minute, then shut down.

When starting i advance the throttle a bit (30 degrees).

by the way, i discovered today, carb is totally dry. the fuel lines were empty as well. I checked tank, lines, pump (by attaching line to separate tank) all work fine. So I will have to check the carb now, could be a problem there.
 
may try letting it run longer, before shutdown....like 5 minutes and do so with increased idle RPM - 1000-1200 RPM.....and maybe opening the throttle to half way.

Lack o fuel is a problem...good luck on that troubleshooting.
 
Hi
got it up and running again.
successful trip, let is run above idle for a while, like you said. I could re-start, so that's good.

What i notice, when the engine is warm, if i put it in gear after running idle, then accellerate, the engine wants to stall and sometimes does, looks like it does not get enough fuel at this stage. All this is the case since installing new refurbishe carb in 2017. maybe needs adjusting.

thanks
 
Back
Top